law get_append_r

lawful-arrays@0.1.0.0 · proof_base.bend:330

import Base

330# From index length(xs) on, xs ++ ys reads like ys.
331law get_append_r:
332  for -A: Data
333  for +xs: List<&2, A>
334  for +ys: List<&2, A>
335  for +i: Nat
336  for e: {Nat.is_lt(i, List.length(&2, A, xs)) == False{} : Bool}
337  {List.get(&2, A, List.append(&2, A, xs, ys), i)
338    == List.get(&2, A, ys, Nat.sub(i, List.length(&2, A, xs))) : Maybe<&2, A>}